Halfling Sorcerer in Shifting Passages
I prepped Binlor at the start to ensure access to wall-breaking, then also prepped GG so after piety farming I could convert into him while still 1st level. Dracul was the third deity, giving a hilariously easy end-game conversion option. With a Vampiric Blade in the shop pool, you can even join him earlier if you like (although the dungeon is a bit undead-heavy today, so you probably want to thin it out a bit first). Lots of easy level-up fodder, with Goats, Bandits, and Wraiths. The natural glyph spawn includes HALPMEH, CYDSTEPP, and BLUDTUPOWA so you have lots of options to generate piety with GG or Dracul or just use these wonderful glyphs. To make things even more overkill, the subdungeon is Zombie Money! The only downside is that there is no natural wall-breaking or declogging glyph that spawns in, so I do advise taking Binlor if you want to play safe. Overall, this is about as easy as shifting passages is going to get.